Earlier in the day, leaders Manchester City survived a spirited Leicester City fightback to earn a thrilling 6-3 victory and Arsenal cruised to a 5-0 win at bottom side Norwich City to consolidate fourth.

Lukaku has not started a league game since picking up an injury in October and missed the last two games after testing positive for COVID-19.

But the Belgian transformed his team after coming on, providing a constant threat, putting his side ahead and then earning the late penalty that secured the three points for Thomas Tuchel's side.

Third-placed Chelsea, who had drawn with Everton and Wolves in their previous two games, are now level with second-placed Liverpool on 41 points - six behind City.

Villa had taken the lead in the 28th minute when Matt Targett's cross deflected in off Chelsea defender Reece James.

The visitors levelled six minutes later when Callum Hudson-Odoi was brought down and Jorginho coolly converted the penalty.

Halftime substitute Lukaku made a swift impact, getting in front of Tyrone Mings to angle in a fine header and put Chelsea ahead in the 56th minute.

In added time, Lukaku was brought down inside the box and Jorginho again made no mistake from the spot to secure three points.

"We are the hunters now. The last results were not the best and now we have to chase. We have to treat every game like a final. Today we won and now we have to push on," Lukaku said.

With second-placed Liverpool not in action after their clash with Leeds was postponed due to COVID-19 cases at the Yorkshire club, City appeared out of sight midway through the first half at Etihad Stadium.

The in-form champions raced into a lead through Belgian midfielder Kevin De Bruyne before a Riyad Mahrez penalty put the hosts in control.

Ilkay Gundogan and a Raheem Sterling penalty gave the hosts a four-goal lead inside 25 minutes.

Leicester stormed back in the second half with James Maddison, Ademola Lookman and Kelechi Iheanacho finding the net.

Aymeric Laporte's 69th-minute header and Sterling's late second secured the champions' ninth Premier League win in a row.

"We just had to control the game," Sterling told the BBC.

"At 4-0 up you have to kill the game.

"Leicester have some really good players. They didn't get disheartened and kept going. Credit to them."

Arsenal thumped a hapless Norwich thanks to a Bukayo Saka double either side of a Kieran Tierney strike, before late Alexandre Lacazette and Emile Smith Rowe goals.

"In general, collectively and individually, we had some big performances. You don't win 5-0 away from home if you don't do that so I'm really pleased with all the boys," Gunners manager Mikel Arteta said.

Harry Kane, Lucas Moura and Son Heung-min goals at Tottenham Hotspur Stadium saw off fellow Londoners Crystal Palace to stretch their unbeaten Premier League run under new manager Antonio Conte to six games - moving them up to fifth and above the Hammers.

Elsewhere, Southampton beat West Ham 3-2 and Brighton defeated Brentford 2-0.

Australian Associated Press